This invention relates to a multiple terminal switch apparatus and particularly to such an apparatus including five possible contacts for selectively controlling circuit connections between corresponding five multiple terminals.
Keylock switch structures are often used for controlling of electrical circuits. In many applications, cost factors are of a substantial significance and the security requirements are not equivalent to those required in various applications using conventional tumbler locks. A practical and low cost keylock switch apparatus is disclosed in the, applicant's co-pending application Ser. No. 07/414,914 entitled "Key Lock Apparatus" filed on even date herewith and assigned to a common assignee herewith. As more fully disclosed in such application, a keylock apparatus is illustrated having an outer housing with an internal bore within which a rotatable lock assembly is secured and direct coupled to a rotating contact assembly. The keylock system includes a pair of spaced locking levers having a control leg and a lock leg. The levers are pivotally mounted within the housing bore with a resilient biasing of the locking legs into locking engagement with a groove on the inner bore of the housing. The control legs have inward projections and an inner enlarged opening defining truncated projections. The key includes a large head for pivoting of the levers to release the lock legs and a following truncated recesses complementing the projections. The large portion simultaneously moves the control legs into locking engagement within the grooves. Only when the key has the truncated recess portion aligned with the truncated projections of the control legs, are the levers appropriately located to hold both the lock legs and the control legs within the rotatable tube and thus spaced from the grooves to permit rotation of the tube in an interconnected contact carrier. The rotatable lock tube includes a projecting end projecting into coupling engagement with corresponding aligned portions of a contact carrier. The illustrated embodiment of the invention shown therein includes a single pair of contact terminals located within an outer wall of the housing. The contact carrier includes a bridging contact for selective engagement with the pair of fixed contacts.
Various applications however require multiple contacts for controlling a plurality of circuits. Ignition systems, particularly off road vehicles, are a typical example. A relatively simple keylock system is often provided. Depending upon the particular features and controls, multiple contacts and various terminal are required. Generally, a range of keylock switch units are required with four or five control terminals. The unit preferably requires a relatively low cost but reliable long life rotary apparatus for selectively positioning of a contact carrier connecting power to the several control contacts. Further, the contacts should be located such that common terminals can be selectively secured to a standard housing structure, thereby minimizing the assembly and component cost.
Various multiple contact keylock units are disclosed in the prior art. The prior art generally provides separate designs and constructions for the different applications. The prior art custom design does not provide a highly effective and low cost structure providing a simple configuration for adaptation to two, three, four, five and six terminal controls.